Returned from the Deere dealer a little while ago after dropping off my 4720 for service and talking to the salesman about ZTRs. I asked him about problems with the EFI engine and none that he was aware of. Deere’s EFI engines are made by Kohler, the ones with a carb are made by Kawasaki. I did a test run of a Z945M EFI with the tweel ‘tires’ with suspension seat and then for comparison another model with the usual pneumatic tires and a non-suspension seat. Humongous difference in comfort, I felt like I was floating over the ground with the tweel tires and suspension seat. The exact opposite with the other Z Track. The other Z Track was a carb model and it was a little fussy to start and stay running. The EFI engine started right up and idled nicely. The only negative and a very minor one is the EFI engine is a bit noisy but I always wear hearing protection when mowing so that’s a non issue.
The Z945M they had was a 52” deck but there’s one with a 60” deck at the other nearby dealer, the salesman is going to pick it up in the morning and give me a call. There’s a 99.9% chance that one will be on my trailer tomorrow.